Leviticus 5:9

7“‘If he can’t afford a lamb, then he shall bring his trespass offering for that in which he has sinned, two turtledoves, or two young pigeons, to the LORD; one for a sin offering, and the other for a burnt offering.

8He shall bring them to the priest, who shall first offer the one which is for the sin offering. He shall wring off its head from its neck, but shall not sever it completely.

9He shall sprinkle some of the blood of the sin offering on the side of the altar; and the rest of the blood shall be drained out at the base of the altar. It is a sin offering.

10He shall offer the second for a burnt offering, according to the ordinance; and the priest shall make atonement for him concerning his sin which he has sinned, and he shall be forgiven.

11“‘But if he can’t afford two turtledoves or two young pigeons, then he shall bring as his offering for that in which he has sinned, one tenth of an ephah of fine flour for a sin offering. He shall put no oil on it, and he shall not put any frankincense on it, for it is a sin offering.